People will cheat if the tournament's not run the right way. I used to play in pre-releases and other limited tournaments for another card game and we never had a cheating problem. They would assign everyone seats, hand out packs, and hand out card lists. Then, you would open your packs, fill out the card lists with all cards, then hand it back to the organizer, who would give your cards with the list to someone random. That way, there is no cheating going on and you can make it a sanctioned event.